Shedding light on dark DNA Most textbook definitions of evolution state that it occurs in two stages: mutation followed by natural selection. DNA mutation is a common and continuous process, and occurs completely at random.
The average adult only eats 15 grams of fiber per day. Women need 25 grams of fiber per day, and men need 38 grams per day, according to the Institute of Medicine.
How much fibre should I eat every day? A rough estimate of the amount you need is about 18g a day, though 16 - 24g is a healthy range and individual requirements vary. Ideally you should aim to open your bowels at least once a day and not have to strain when you go to the loo. One example of what you'd need to equal about 18g is a bowl of bran cereal for breakfast, a wholemeal sandwich with a bowl of salad for lunch, and five portions of fruit and vegetables.